The present invention relates to a battery pack which can attach to electrical equipment regardless of the orientation of its front and back sides.
Battery packs in general use today have positive and negative (+ -) charge-discharge terminals disposed in opposing locations on the end of the case. If this type of battery pack is attached to an electrical apparatus with the front and back of the battery pack inverted, the + - polarity will be reversed. The electrical apparatus may malfunction when the battery pack is connected with reverse polarity. In addition, large currents can flow in the battery pack and electrical apparatus resulting in heating to abnormally high temperatures.
To prevent these harmful effects, battery packs have been configured so they cannot be connected with reverse polarity. Namely, the battery pack and electrical apparatus have been made in special shapes that allow attachment in one orientation only. As a result, the battery pack and the battery pack attachment section of the electrical apparatus must be formed in complex shapes. In addition, the user must determine the proper battery pack attachment orientation judging from the shapes of the battery pack and the electrical apparatus. This makes it more difficult to simply attach the battery pack to the electrical apparatus. Therefore, this system also has the drawback that children, the aged, and users who are not mechanically inclined cannot use it conveniently.
This drawback can be eliminated by a battery pack configuration that allows attachment without regard to the orientation of the front and back of the battery pack. Namely, this drawback can be eliminated by a battery pack which can be rotated 180.degree. and still be attached. A battery pack which realizes such a configuration is cited, for example, in Japanese Non-Examined Utility Model Publication No. 2-12157 issued Jan. 25, 1990. As shown in FIG. 1, the battery pack cited in this disclosure has a positive charge-discharge terminal 102 disposed at the center of one end of the case 101 and negative charge-discharge terminals 102 disposed on both sides of the positive terminal 102. This results in attachment without specified orientation.
The battery pack shown in FIG. 1 can reliably connect its + - charge-discharge terminals 102 to the electrical apparatus even when the battery pack is rotated 180.degree. and attached with the front and back reversed. Therefore, it has the feature that it can be easily attached while ignoring the attachment orientation. However, this type of battery pack has the drawback that it is difficult to accurately mount the charge-discharge terminals 102 in the specified locations on the case 101. Further, since the + - charge-discharge terminals 102 which are exposed outside the case 101 connect internally through leads 103, assembly of this structure is difficult. Finally, this structure also has the drawback that it is difficult to reliably prevent internal short circuiting of the + - leads 103 and the charge-discharge terminals 102.
The present invention was developed to overcome these and other drawbacks. It is thus a primary object of the present invention to provide a battery pack which can be attached independent of orientation wherein the + - charge-discharge terminals can be simply, easily, and accurately mounted in the specified locations on the case without short circuiting.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.